Performance of a photo-heterotrophic, hypersaline system for intensive cultivation of white leg shrimp (Litopenaeus vannamei) with minimal water replacement in lined ponds using a stochastic approach

Abstract

The aim of the study was to evaluate the performance of Litopenaeus vannamei in an intensive photo-heterotrophic hypersaline system with minimal seawater replacement, and establish relationships between parameters of a stochastic production model and relevant water quality variables. Six experimental 1000 m 2 lined ponds were stocked at a density of 120 shrimp m À2 for a 105-day trial. Salinity increased from 37 to 45 AE 2 g/L, and the water level was maintained with the weekly addition of filtered seawater, equivalent to 1.6% per day. The stochastic model predicted that, at harvest, there is 95% confidence that the system produces between 12.1 and 14.7 t/ha with a mean final individual weight of 13.1 g and a mean survival of 84.2%. Sensitivity analyses showed that dissolved oxygen and individual final weight of shrimp were the main variables influencing yield variance.Nitrogenous compounds were maintained between optimal cultivation levels (NH 3 -NH 4 + = 0.73 AE 0.43 mg/L, N-NO 2 À = 0.09 AE 0.05 mg/L, N-NO 3 À = 3.22 AE 0.11 mg/L). Heterotrophic bacteria (6.6 AE 3.4 9 10 5 CFU/ml) and chlorophyll-a concentration (108.5 AE 80.2 lg/L) showed a similar development pattern, indicating a strong relationship between bacteria and microalgae during cultivation. Vibrio spp. concentrations were low (1.24 AE 1.42 9 10 3 CFU/ml). It was shown that the photo-heterotrophic system could be used in hypersaline conditions, typical of semi-arid regions, to consistently produce between 12.1 and 14.7 t/ha in 15 weeks. K E Y W O R D Shypersaline, intensive cultivation, Litopenaeus vannamei, minimal seawater replacement, photo-heterotrophic, stochastic modelling

Bioeconomic modelling of the intensive production of white‐leg shrimp (Litopenaeus vannamei) in a photo‐heterotrophic hypersaline system, with minimal seawater replacement

“…Similarly to the results obtained by Moreno‐Figueroa et al . () for the spring‐summer cycle, the equation developed by Ruiz‐Velazco et al . () (Eqn 2) fitted shrimp growth data adequately for the summer‐autumn cycle, yielding significant results regarding regression anova (Fig.…”

“…As explained in the study by Moreno‐Figueroa et al . (), following the above‐described methods, the values resulted in k = 1.067 − 0.0031( T ), and z = 0.017 − 0.0030(DO) for the spring‐summer cycle.…”

“…Nowadays, systems with zero or minimum water exchange have proved to be more efficient regarding biosecurity and energy use (Avnimelech ; Moreno‐Figueroa et al . ). The photo‐heterotrophic system using plastic‐lined ponds, also known as ‘green‐floc’, ‘semi‐biofloc’ or ‘mixotrophic’ (McIntosh ; Shishehchian ; Huda et al .…”

“…), maintains adequate water quality for shrimp cultivation in semiarid regions, with minimum water replacement and hypersaline conditions (>45 g L −1 ) (Moreno‐Figueroa et al . ).…”

“…A stochastic model was developed describing the production dynamics, and together with data collected in a spring‐summer cycle from a previous study (Moreno‐Figueroa et al . ), we conduct a bioeconomic analysis by comparing both cycles. Our main objective was to evaluate the productive and economic performance of shrimp when reared in our cultivation system, assessing uncertainty in production and economic indicators and defining optimal harvesting strategies.…”